Page 459 - Decision Making Applications in Modern Power Systems

418 Decision Making Applications in Modern Power Systems

time series measured in discrete time slots ½1; ... ; kŠ for any charging session
on the same day. Our previous work describes the framework with the fol-
lowing key structures/assumptions: (1) The order of the measured power
in time series is preserved (because the power that EVSEs draw is depen-
dent on the SOC of the EV being charged) and (2) the charging is preemp-
tive, which means that the rescheduled charging load is equal to the
original and the charging tasks are interruptible without any decrease in
the SOC of the EV.

16.3.1 Tariff and demand response markets
The AlCoPark garage is in Pacific Gas and Electric’s (PG&E’s) E-19 time-
of-use (TOU) service rate shown in Table 16.1. This rate plan is suitable for
customers who can be more flexible with their power usage between the
maximum peak, maximum part-peak, and off-peak periods. Electric demand
is averaged over 15-minute periods to determine peak values in each
monthly billing period type (e.g., maximum peak maximum part peak).
Typically, the demand charge cost accounts for about 50% of the total elec-
tric utility cost for nonresidential facilities. For example, there would be
$114 savings by shifting the demand of a single 6.6 kW level 2 charging

TABLE 16.1 PG&E E-19 rate schedule.
$/kW Time period
Demand charges
Maximum peak demand summer $18.74 12:00 6:00 p.m.
Maximum part-peak demand $5.23 8:30 a.m. 12:00 p.m. and
summer 6:00 9:30 p.m.
Maximum demand summer $17.33 Anytime
Maximum part-peak demand $0.13 8:30 a.m. 9:30 p.m.
winter
Maximum demand winter $17.33 Anytime
Energy charges
Peak summer $0.15 12:00 6:00 p.m.
Part-peak summer $0.11 8:30 a.m. 12:00 p.m. and
6:00 9:30 p.m.
Off-peak summer $0.08 Anytime
Part-peak winter $0.10 8:30 a.m. 9:30 p.m.
Off-peak winter $0.09 Anytime